(1) All export duties shall be finally payable at the rate in force when the goods are actually exported but in the first instance payment shall be made by the owner to the Collector at the rate in force when the goods are entered for export.
(2) Duty imposed on coal by the Customs Tariff (Coal Export Duty) Act 1975 shall be payable at the rate in force when the coal is exported and shall be paid before the coal is exported or within such further period as the Collector allows.
(5) Duty imposed on Alligator Rivers Region uranium concentrate by the Customs Tariff (Uranium Concentrate Export Duty) Act 1980 shall be payable at the rate in force when that concentrate is exported and shall be paid before that concentrate is exported or within such further period as the Collector allows.